Management of radiation-induced nausea and vomiting (RINV) includes both prevention and therapy. Primary prevention involves implementation of measures to modify risk factors. Secondary prevention involves prophylaxis and treatment with 5HT(3) receptor antagonists (5HT(3)RAs) with or without corticosteroids, dopamine antagonists, antihistamines, or anticholinergics. 5HT(3)RAs are also useful in treatment of RINV with significantly better outcomes, compared to other antiemetics or placebo. Agents include ondansetron, granisetron, dolasetron, palonosetron, and tropisitron. These agents may be useful in both the radiotherapy patient and the individual who has been accidentally exposed to ionizing radiation.